Fire alarm system



Oct. 9, 1934. .1. M. JOHNSON FIRE ALARM-SYSTEM I Filed July 21} 1928 sSheets-Sheet 1 INVENTOR.

ATTO EY LLUCI WOZEUIL.

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Filed July 21, 1928 8 Sheets-Sheet 2 Q SQ INVENTOR.

.1. M. JOHNSON FIRE ALARM SYSTEM Get. 9, 1934.

8 Sheets-Sheet 3 Filed July 21, 1928 n03 MW 301 UOOO a & Pm m E/HM m QINVENTOR.

Ja/mMJahrzsan jrromvg J. M. JOHNSON 1,976,347

FIRE ALARM SYSTEM Filed July 21, 1928 8 Sheets-Sheet 4 INVENTOR.JahlzfiJolznson 521m H ATTOREY Get. 9, 1934.

Oct. 9, 1934. J M. JOHNSON 1,976,347

FIRE ALARM SYS-TEM Filed July 21, 1928 8 Sheets-Sheet 5 II n INVEN TOR.

Jo/v'zMJohnson BY &

ATTO EY Oct. 9, 1934.

J. M. JOHNSON FIRE ALARM SYSTEM Filed July 21, 1928 8 Sheets-Sheet 6illll! IN V EN TOR.

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jg ATTORNEY Oct. 9, 1934.

J. M. JOHNSON FIRE ALARM SYSTEM Filed July 21, 1928 8 Sheets-Sheet 7 INVEN TOR.

JaimMJo/msmv JZLI g ATTOR EY Oct. 9, 1934. J. M. JOHNSON FIRE ALARMSYSTEM Filed July 21, 1928.

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ATTO EY Patented Oct. 9, 1934 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to improvements in an automatic fire alarmsystem, and refers more particularly to a system which is positive inaction and which operates on a closed circuit from a central battery, nolocal batteries being used. The system provides transmission of a firealarm signal from a protected building or residence in the event offire, to the central oilice, recording by code signal the location ofthe fire.

The system also provides for trouble alarm, that in the event that thehouse or building line is broken or one side of the thermostataccidentally released, that this rupture will be recorded by a specialcode signal transmitted to the central ofilce. The system furtherprovides for an emergency fire alarm so that in the event one of thehouse lines is broken, the system is still operative for an emergencyfire alarm, as the house lines are duplicated and therefore afforddouble protection.

A signal is also provided in the event the current in the lines isdiminished below a normal operating value, under which circumstances asignal is recorded in the central oilice.

Further novelty lies in the transmitter and the automatic drop,controlling the minimum circuit requirement for the closed circuitsystem.

One of the principal features of the system lies in the fact that it isoperated on the principle of opening the circuit rather than making acontact, which assures operation and eliminates the possibility of bador ineffective contact where an open circuit is used. 7

In order to describe the details of the system and its operation thereare offered four wiring diagrams, and in order that the circuits may bereadily traced, the path of the circuit is indicated in heavy lines.

Fig. 1 is a diagram of the wiring, showing the normal position of thesystem and the flow of the current at this time.

Fig. 2 is a wiring diagram of the fire alarm position after thethermostatic connections have been broken.

Fig. 3 is a trouble alarm position after the disruption of the positiveor negative wire.

Fig. 4 is a Wiring diagram of position after alarm has been transmitted.

Fig. 5 is a side elevational view of'the transmitter.

Fig. 6 is a top view of the transmitter.

Fig. '7 is a View of the transmitter, taken along the line 77 in Fig. 6.

Fig. 8 is an end view of the transmitter.

Fig. 9 is a view taken along the line 9--9 in Fig. 6.

Fig. 10 is a bottom view of the transmitter.

Fig. 11 is a side view of the main circuit control drop.

Fig. 12 is a bottom view of the drop shown in Fig. 11

Fig. 13 is a detail of the restoring button which swings the drop backinto operable position.

Referring to the drawings:

The system operates through a central ofiice and employs two sets ofbatteries, one main battery and one local battery. The main batteryoperates the main line instruments and the local battery operates thesignal light and buzzer which are positioned on the central ofiicepanels hereinafter described. The main line battery'may be common or abattery for each circuit. The main signal line may connect as many asfour transmitters, one transmitter for each floor of the building, eachwith a diiferent code.

From the transmitter house wires will be connected in looped circuitswith thermostats which are placed on the ceiling, preferably onethermostat to each 144 square feet.

In the event of fire the heat rising to the ceiling causes thethermostat to break the circuit which functions the transmitter torelease, thereby recording the alarm signal at the central office.

The system may be divided into three main parts, first the panelpositioned in the main office upon which is mounted the mechanism,visual and auditory and record instruments by means of which the alarmsare registered and through which the operator is informed of trouble aswell as the location of the trouble and fire. Second, the transmitterwhich constitutes a mechanism which through energized coils functionscode and shunt switches which in turn manipulate the proper signal orsignals on the recording panels in the central ofiice. Third, thethermostat loops which are positioned in the dwellings or oflicebuildings, or thermostats, may be afiixed to any type of mechanicalmechanism such as bearings or the like where it is desired to determinewhen excessive temperatures exist. The latter purpose, namely, the useon bearings or machinery, offers a large field for a system of thischaracter in order that a central oflice control may be maintained uponlarge plants or large machine installations.

Referring now to the diagram of Wiring shown in Fig. l, which representsthe system in normal position, the current will be followed from thebattery to the operating board through the transmitter and house line.

The current from the battery 1 passes through the positive feed wire 2and fuse 3, wire 4, milliampere meter 5, wire 6, to a drop whichconsists of a coil 7, drop contact 8, resistance 9, thence through wire10 to the punch register 11, shown diagrammatically inasmuch as theconstruction is known to the art, wire 12 to the variable resistance 13,wire 14, to the telegraph key 15, wire 16 to the line jack 17, main linewire 18 to the positive binding post 19, thence through transmitter wire20 to the code switch 21, wire 22 to the transmitter binding post 23,house wire 24 to the thermostats 25, which may be of any suitableconstruction returning to the transmitter binding post 26, wire 2'7, tothe binding post 28, wire 29 to the negative binding post 30, wire 31 tothe binding post 32, thence through the house wire 33 to thermostats 25,returning to transmitter binding post 34, wire 35 to code switch 36,wires 37 to binding post 38 and by the main .llne wire 39 to the linejack 40, thence by wire 41 to the relay 42 and by wire 43 to tap bell44, finally returning to the main battery 1 through wire 45, fuse 46 andwire 47. It will be seen that the magnets 48 and 49 are shunted in theman ner described above.

Referring now to Fig; 2, which shows a system in fire alarm position.

Assuming that one of the thermostats 25 has released both sides of thehouse wire 24 and 33 which are opened by the functioning of thethermostat. The path of the current will now j be through the magneticcoil 48, code switch 21,

49, wire 53 to the negative binding post 30 and thence to the negativeside of the battery through the main line wire 39. It is evident thatboth of the coils 48. and 49 are energized, which causes armatureshereinafter described, in Fig. 5, to release a spring driven motor shownin Fig. 7,

which rotates the code wheel and functions by opening, as will behereinafter explained, the code switches 21 and 36, in accordance withthe digits of the code wheel. The digits of the code wheel identify theexact location from which the fire alarm comes. This functioning of thecode wheel causes the recording instruments at the registering panel tooperate to correspond with the opening and closing of the circuit. Thetap bell 44 will tap the signal. When the circuit opens, the drop 7 willbe released, causing the double contact 8 and 55 to close. The punchregister 11 will perforate holes in a paper tape in accordance with theopening and. closing of the circuit.

The relay 42,bei;-g provided with double contacts 56 and 57, willoperate the master register 56 through the contact 56, while contact 57operates the light'slgnal 59. The relay contacts 56 and 57 are normallyopen. The drop contacts 55 close the circuit to the buzzer 58 so thatthe buzzer which is an audible signal, will function with the signallamp and master register according to the code signal produced at thetransmitter.

The current from the local battery 61 is now flowing through the feedwire 62, wire 63, fuse 64, wire 65, wire 66, to light the signal lamp59. Current also passes through wire 67, drop contact 55, wire 68 to thebuzzer 58, thence through wire 69 to-the silencing switch 60.

The negative side of the local battery is connected to the circuitthrough the wire 70 and wire 71, fuse 72, wire 73, to the binding'postof the silencing switch 60 to which there is also connected wire 74which connects to one of the contact members of the relay contact 57. Aseparate wire 75 communicates between one of the contacting members ofthe relay contact 57 and a contacting member of the adjoining relaycontact 56. From the opposite contacting member of the relay contact 56is a wire 76 communicating with the master register 56.

It will now be evident that when the drop 7 is released and the contact55 completes the circuit, the buzzer will operate continuously, callingthe operators attention to fire or trouble alarms. The relay will alsobe functioned by the code wheel of the transmitter to register by thesignal lamp, tap bell and punch recorder the location of the fire.

Referring now to the wiring diagram shown in Fig. 4, which discloses thesystem at a position after an alarm, the path of the current from thepositive wire 18 is through the code switch and shunt switch 77 thencethrough wire 79, wire 51 to the positive binding post 28, thence throughwire 29 to the negative binding post 30. The negative side is connectedup from the line 39 through binding post 38, wire 37 through code switch36, wire 35, wire 52 and wire 80 with shunt switch 78 connecting withthe binding post 30 of the transmitter through wires 81 and 53. Thus itwill be seen that in this after alarm position the transmitterautomatically closes the shunt switches and the main line is again innormal position with the house line, so that all that is necessary toput the house lines again in the sys-' tem is to reset the thermostatand the transmitter to open theshunt switches and elinfinate theenergizing coils 48 and 49 from the system.

Referring to the wiring diagram shown in Fig. 3, which represents thesystem in what is known as trouble alarm position, and assuming that thehouse wire 24 is broken at A in Fig. 3, which has caused the magneticcoil 48 to energize, permitting the code wheel to make a revolution,which is automatically functioned as hereinafter explained in connectionwith the description of the transmitter. This one round of the codewheel gives notice to the operator that one side of one of the houseloops is open. In this position it will be noted that the house wirewhich constitutes the automatic loop, still remains closed with currentpassing therethrough; Now in the event that fire should occur beforerepairs are made, the system is operative for emergency fire alarms thesame as in normal operating position. The current in this positionpasses through the wire 18 and code switch 21 thence through wires 54and 50 to the coil 48, out of the coil through wire 51 to the bindingpost 28, wire 29 to binding post 30, through wire 31 to binding post 34,thence through the operative house loop 33 back to binding post 34 andthence through wire 35 and code switch 36 to binding post 38 which isconnected to the main line wire 39. In this position is shown a positiveline broken, but functioning of the system would be identical in so faras results are concerned were the negative line 33 broken, ex-

cept that the other coil 49 would be energized. In the trouble alarmposition the code wheel of the transmitter has, made only one revolutionand should a fire occur at this time, the rupture of the remainingoperative line 33 would release the transmitter, permitting the codewheel to make the remaining revolutions to register proper fire alarmsignals upon the panel in the central oilice.

It will be noted in Fig. 2, which is fire alarm position, that both dropcontacts'are in a closed position so that current passes through thedrop instead of through the permanent resistance 9. When the drop is inthe ready position the current passes through the permanent resistancewhich reduces the current to a very low point, but immediately upon thedrop operating, the contact 8 is closed, which cuts out the resistance,shunting the current through the drop contact. In other words, undernormal position it is only desired to allow enough current to passthrough the circuit to keep the system under test, which is not asufficient current to operate the system in transmitting signals.Therefore, when the drop contact closes, the circuit is increasedsufficiently to operate the various registering instruments on thepanel, which are interposed in the line of the circuit. The use of thedrop in this manner is of considerable importance, as it affords a greatsaving of electrical energy.

In order that the mechanical operation of the transmitter may beunderstood it has been detailed in Figs. 5, 6, 7, 8, 9 and 10. Inexplaining the operation thereof, reference will be made also to Figures1, 2, 3 and 4, which show the wiring and path of the current in variouspositions of the transmitter.

The transmitter in Fig. 5 is set in a position ready to transmit alarmsignals.

The transmitter is operated by a spring motor which is wound up by a keynot shown, inserted upon the arbor 82, the end of the key engaging astop or cam 81 fixedly attached to the arbor. The spring motor causesthe code wheel to rotate at a given speed. The release of thetransmitter is controlled by the electromagnetic coils 48 and 49 showndiagrammatically in the wiring diagrams and in Figs. 5, '7 and 9 of thedrawings.

The number of rounds or rotations of the code wheel at the time of firealarm signals is governed by the stop cam 81 shown in dotted lines inFig. 5, which, as stated, is fixedly mounted upon the arbor 82 and moveswith the same, engaging the stop pin 83 in its rotation. The stop pin 83may be set to allow the code wheel to rotate two rounds or more. Theincreasing of the number of rotations is effected by moving the pin 83into adjacent screw holes such as shown at 83 When the system issignaling trouble alarm the code wheel makes one round by reason of thestop lever 84 upon which is mounted a pin 85 shown in Fig. 9. The lever84 is supported in substantially a horizontal position by means of thelevers which are set by the key through an engaging lever 86 and lever84*. The pin 85 en gages a contacting pin which is permanently mountedin the pinion wheel 88, thereby arresting rotation of the gear 88 afterone revolution which constitutes trouble alarm. The pinion wheel isfixedly mounted on the main arbor 89 upon which is also mounted the codewheel, so that the code wheel 80 and pinion wheel 88 rotate in unison.

It should be understood in this connection that the lever 86 and levers90 operate independently and that any one may hold the lever 84 insubstantially a horizontal position as suggested. The lever 84 and lever86 comprise a mechanism which is nothing more than a setting device forthe levers 90. In fire alarm position, it will be noted that currentflows through the coils 48 and 49, which causes the armatures 91 and 92shown in Fig. 6, to be drawn to the coils 48 and 49, the armatures 91and 92 being connected to the release arms 94 and 93 respectively. whichare pivoted at 95 and serve when actuated by the circuit to raise thelock lever 96, also pivoted at 95. This frees the escapement lever 97which contacts the end of the lock lever 96, releasing the escapementlever 97 and allowing the spring motor to rotate the code wheel 80. Asthe code wheel rotates, the notches 98 of the code wheel raise the codeswitch lever 99 shown in Fig. 5, in accordance with the number ofnotches on the code wheel, thus functioning withthe passing of eachnotch, the code switches 21 and 36 shown in Figs. 5 and 9. Thisfunctioning of the code switch causes the signal to be recorded aspreviously described, it being understood that at the same time theshunt switches '7'? and '78 shown in the wiring diagrams and in Fig. 7,are closed. It will be noted that the contacts of the shunt switches 77will be closed as the armature 92 is drawn to the coil 49 whichoperation raises the release lever 94 sufficiently to allow the lever100 to move forward under the pressure of the spring 101 which operationcloses the contact shunt switch 77, allowing the current to fiow asshown in Fig. 3. It will be understood that in fire alarm operation bothlevers 100 and 102 move forward due to spring action, closing thecontacts of both shunt switches '77 and 78.

It can readily be seen that in the event either of the coils 48 or 49are energized, its armature will cause the operation of theleverafiected, closing the contact of the shunt switches for thatposition. It will also be seen that the release of the spring motor iscontrolled by raising the lock lever 96 (see Fig. 6) which lever iscommon to both release levers 93 and 94 by means of the cross bar 103.It will be understood that. when coils 48 and 49 are de-energized by theshunts, that levers 100 and 102 having rroved under the toe of thelevers will prevent their moving to locking position set free by thewinding operation hereinafter described.

In rewinding the transmitter the end of the key also contacts the end ofthe arm 86 which is fixedly mounted on the arbor 86 upon which is alsomounted the lever 86. This latter lever 86, besides raising the lever 84by contacting a transverse stud 84 extending from the end of the lever,also turns arbor 86' when raised by the key. Two arms 90, shown in Fig.10, are fixed to said arbor and actuate the lever 100 and the other tolever 102, to move them from beneath levers 94 and 93 and to lockingposition. .The lever 100 and lever 102 are functioned by the coils 48and 49 through pivoted lever arms 93 and 94. When but a single coil isenergized, one arm being functioned will tripthe lever 96 by contactthrough the cross piece 103. This lever 96 trips the stop 9'? pivoted at9'1 (see Fig. 9) and releases the catch 97*. This permits rotation ofthe arbor 89 produced by the gear drive mechanism from the motor untilthe stop pin 87 on pinion 88 contacts the pin 85 on the arm 84. Thisconstitutes one revolution of the code wheel 80, and during thisrotation signals are transmitted due to the teeth 98 of the code wheelraising the lever 99 to function code switches 21 and 36.

When the remaining coil of the transmitter is energized, its arm willdrop the other lever 90 which alone supports the lever 84, permittingthe pin 87 to pass the pin 85, and the motor to continue to rotate thecode wheel so that the code wheel will signal fire alarm through thecode switches and main circuit to the receiving boards. The rotation ofthe code wheel is finally arrested when the stop cam 81 meets the stoppin 83 (see Fig. 5). The number of rotations of the code wheel isgoverned by the positioning of the stop in. 4 p The automatic drop whichcontrols the minimum current requirement for the system comprises asupport 104 shown in Fig. 11, upon which is mounted a secondary supportmember 105, and to this is attached the permanent resistance 9. Upon thesupport 104 is mounted the coil '7 and the double drop contact switch 8.One of these switches controls the resistance, the other the localcircuit signals including the signal light 59 and buzzer 58. The support104 is attached as shown to the panel 106 of the signal receiving board.The wiring of thedrop is shown in the wiring diagram (Figs. 1 to 4) andis omitted from Fig.,11 and Fig. 12 in the interest of simplicity.

Pivoted at 107 is the armature drop 108 which is normally held in theposition shown in Fig. 11 by the current passing through the coil 7.When the current diminishes beyond a certain predetermined amount, theweight of the drop 108 overcomes the attraction of the current in thecoil and permits the drop to fall into a position shown in dotted linesin Fig. 11, at which time the numeral at the bottom of the drop shown inFig. 12 is swung down so that it is exposed at the front of the panelthrough an aperture in the front of the panel. At the end of the pivotedarmature 108 is an adjusting screw 110 which regulates the contactbetween the armature and the trouble contact switch 8. When the drop hasbeen operated by failure of sufficient current passing through the maincircuit or system and after the trouble has been repaired, the drop maybe returned to position by means of a restoring button 111 shown in Fig.11, and in detail in Fig. 13. The restoring button works against aspring 112 and has a parallel rod or bar 113 which contacts the front ofthe armature drop and swings it back into position as shown in Fig. 11,where the current in the coil holds it and keeps the double contactswitch open so thatthe circuit passes continuously through the permanentresistance 9 until the drop falls and permits the switch to close. Asheretofore suggested, the weighted armature or drop determines theminimum circuit requirement of the system until upon failure of thiscurrent it functions and thereby gives notice of failure of the current.

The transmitter and drop mechanism have been developed primarily for aclosed circuit fire alarm system of the character herein described andeach have features and novelty essential to the operation of thisparticular type of system. No attempt has been made todetail the entiremechanism of the receiving board, as a great part of this apparatus isstandard electrical equipment. The system in four of its phases has beendiagrammatically shown to bring out its functioning and disclose thepassage of the current under difi'erent conditions. Supplementing thediagrammatic disclosure of the system are the details of the transmitterand drop mechanism which have been a development essential to the properfunctioning of the system.

The one particular element of novelty in the transmitter is the factthat each transmitter has but two electromagnetic coils to function theshunt and code switches. By the use of but two coils in the transmittera considerable amount of mechanism has been dispensed with, materiallyincreasing the simplicity of the transmitter.

Another advantage of the transmitter mechanism is in the fact that inre-winding the transmitter it is (impossible to reset it for operationas long as there is an open circuit either in the main circuits or inthe secondary house line circuits. Also it is impossible to reset thetransmitter mechanism without completely resetting it in a position fornormal operation. In other words, it is impossible to reset thetransmitter in trouble alarm position or any normal operating positionif the key cannot be removed from the transmitter, and consequently thetransmitter box cannot be closed. The system is capable of beingenlarged to accommodate any desired number of thermostats by increasingthe transmitter and receiving board units. Thus a central receivingstation may have any desired number of receiving boards and the systemmay be increased as population or requirements are increased. v

I claim as my invention:

1. A fire alarm system including in combination, a normally closedcircuit comprising a source of potential, 2. first magnet, a secondmagnet; a shunt circuit containing a thermostat normally shunting saidfirst magnet, a shunt circuit containing a thermostat normally shuntingsaid second magnet, and means operated by one of said magnets for givingan indication when its respective shunt circuit is broken, and means forgiving a different indication when both said shunt circuits are broken.

2. In a fire alarm system including in combination, a normally closedcircuit comprising a source of potential, a code-transmitter having atleast two electromagnets; a shunt circuit for each of saidelectromagnets, said shunt circuits comprising protection loopsextending throu h an area to be protected, said loops being placedadjacent to each other and being provided with thermostats normallyclosing said shunt circuits, a means controlled by one of said magnetsfor giving a code trouble signal when its respective least two closedprotection loops extendingthrough the area to be protected adjacent toeach other, each loop being connected across a correspondingelectromagnet to prevent its effective energization, circuit openingmeans adapted when actuated to open both protector loops, and meanscontrolled by the effective energization of both magnets due to theoperation of the circuit opening means in both loops .to cause thetransmitter to transmit the alarm code and controlled by theenergization of one magnet only due to a break in one of the loops onlyto transmit the trouble code.

4. A protective alarm system as claimed in the preceding claim whereinthe transmitter is provided with means to transmit a single round of thecode signal when one of said magnets is actuated, and a plurality ofrounds upon the energization of both magnets. l

5. A protective alarm system comprising, a normally closed circuitincluding a source of energy, ,a normally inoperative code transmitterincluded in said circuit and having means for transmitting an alarm codesignal and a trouble code signal over said circuit, a pair of means forcontrolling the operation of the transmitter to.

transmit one or the other of said codes, said means being included insaid circuit, at least two olosed protective loops extending through thearea to be protected, each loop being connected across one of saidcontrolling means to prevent its efiective energization, circuit closingmeans adapted when actuated to open both protective loops and meanscontrolled by the effectlveenergization of both controlling means due tothe operation of the circuit closing means opening both loops to causethe transmitter to transmit the alarm code and controlled by theenergization of one controlling means only due to a break in one of theloops only to transmit the trouble code.

6. A fire alarm system including in combination a normally closedcircuit comprising a source or potential, a resistance, a firstelectromagnet,

a second electromagnet, a shunt circuit containing a thermostat normallyshunting said first magnet, a shunt circuit containing a thermostatnormally shunting said second magnet, means operated by one of saidmagnets for transmitting an indication over said closed circuit when itsrespective shunt circuit is broken, means for transmitting a. differentindication over said closed circuit when both of said shunt circuits arebroken and means to shunt said resistance 'when either of said magnetsis effectively energized by the rupture of its respective shunt.

7. In combination a pair of main line wires; a transmitter interposedtherebetween includin a pair of normally deenergized electromagnets andmeans whereby a signal is sent when either magnet is energized and adifferent signal when both magnets are energized; a plurality ofstations; circuits short circuiting the magnets respectively; and aswitch in each station operable to break both short circuiting circuits.

8. In combination a pair of main line wires; a transmitter interposedtherebetween including a pair of electro'magnets normally approximatelyfree of current and means whereby a signal. is sent when current isincreased in either magnet, and a different signal when the current isincreased in both magnets; a plurality of stations;

